Gain control interfaces that allow a user to modify a gain level of an audio signal are often used in multimedia applications. A gain control interface typically contains a control icon that slides across a scale that defines a succession of gain levels (usually measured in dB). By sliding the position of the control icon across the scale, as an audio track is playing, the user can modify the gain level of the audio track during the play.
The distance between two gain levels on the scale can be measured by a number of pixels that are displayed between the two gain levels. A pixel resolution can be defined as a number of pixels per difference in gain levels. Conventionally, the scale is divided into two or more regions where each region has a linear pixel resolution (i.e., as the difference in gain levels increases, the number of pixels between the gain levels increase linearly). For example, in one region of the scale, 50 pixels may be displayed between every 2 dB difference in gain levels. In a second region of the scale, 30 pixels may be displayed between every 2 dB difference in gain levels.
The conventional approach creates a problem, however, since the user does not perceive the gain (i.e., volume) of an audio signal on a linear scale. In other words, conventional gain control interfaces do not allow a user to adjust the gain level of the audio signal in an intuitive manner. Therefore, there is a need for a gain control interface that allows the user to intuitively adjust gain levels of an audio signal in a multimedia application.
The user's adjustments, over a specific time period, of the gain levels of an audio signal can be captured as numerous data events (i.e., a stream of data events) by a multimedia application employed by the user. Each data event has a gain level value that is specified by the user at an instance in time during the time period. A multimedia application uses the data events to provide a graphical representation of the stream of data events during the specific time period. The multimedia application typically positions the data events across a gain level axis and a time-based axis of the graphical representation. A user can then modify the gain levels of the audio signal during the specific time period by changing the position of the data events in the graphical representation of the stream of data events.
Conventionally, a multimedia application will produce a graphical representation of the stream of data events that contains numerous and unnecessary data events that consumes resources of a computer executing the multimedia application. Having numerous and unnecessary data events also makes manipulation of the data events in the graphical representation difficult and cumbersome since numerous data events must be re-positioned to modify the gain levels of the audio signal during a particular time span. For example, in the graphical representation, a conventional multimedia application may display numerous data events in a relatively straight line across a particular time span even though only two data events (the data events at the beginning and ending of the relatively straight line) are adequate. Therefore, in using the conventional multimedia application, a user that wishes to modify the gain levels of the audio signal during the particular time span must re-position each of the numerous data events that are displayed in a relatively straight line across the particular time span.
Therefore, there is a need for a method that reduces the number of data events representing the user's interaction with the gain control interface while still adequately representing the user's interaction with the gain control interface.